The specific objectives of the proposed research are as follows. First, to replicate the finding of the inferiority of pictorial perception relative to real scene controls with previously untested stimulus displays under control conditions creating the best possible match between the surface relation (depth) information contained in the pictures and the real scenes. The creation of such structural equivalence will allow a more precise measure of the effect of the surface, flatness, information present in pictures and absent in real scenes. The design will also test for the effects of media, slides and prints, and station point in order to provide further information about the operation and limits of compensation for perspective distortion. The second objective is to test for the effects of adding surface information to these real scenes and of subtracting it from the corresponding pictures. The intention of these manipulations is to produce pictorial perception with real scenes and ordinary perception with pictorial displays in order to test the hypothesis that the critical difference between pictures and real scenes (monocularly viewed at the correct station point) is the flatness of surface information present in pictures. The third objective is to establish the character of modified perspective which appears natural and correct to the ordinary viewer through the generation and testing of pictures with varying degrees of perspective convergence from linear (conical) to isometric (parallel). The fourth objective is to establish the limits of the ability to compensate for the perspective distortion obtaining at the wrong station point through the generation and testing of anamorphic displays.